X-ray imaging is used for a variety of purposes such as medical imaging and non-destructive testing of industrial components. With respect to medical imaging, many digital imaging devices, i.e., non-film based imaging devices, are known. One such lens-based device is disclosed in U.S. Pat. No. 5,216,250 which is incorporated herein by reference in its entirety.
The '250 device, which is particularly intended for imaging a patient's breast, includes an x-ray source, a compression plate for compressing the patient's breast, a light-tight housing containing a mounted phosphor screen, a lens for focussing light emitted by the phosphor screen and related digital processing equipment. In operation of the '250 device, x-ray radiation is transmitted through the patient's compressed breast and impinges upon the mounted phosphor screen. The mounted phosphor screen, in turn, emits light which is focused by the lens on a charge coupled device (CCD) array of a digital camera so as to produce an image of an area of interest within the patient's breast.
Although lens-based digital imaging devices such as the '250 device are currently being utilized for certain medical imaging applications, some difficulty has been experienced due to the variables encountered in practice. In particular, such lens-based digital imaging systems have sometimes provided less than optimal image contrast and/or resolution for particular medical imaging applications.